Wide-band transparent electrical contacts and interconnects for FPAS and a method of making the same

Patent metadata

Field	Value
Publication number	US-9640680-B1
Application number	US-201414183237-A
Country	US
Kind code	B1
Filing date	Feb 18, 2014
Priority date	Feb 19, 2013
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

An optical device includes an optically transparent and electrically conducting conductor including graphene, a network of metal nanowires, or graphene integrated with a network of metal nanowires. The optical device includes a II VI compound semiconductor, a III V compound semiconductor, or InAsSb.

First claim

What is claimed is:

1. An optical device comprising:
an optically transparent and electrically conducting conductor comprising graphene, a network of metal nanowires, or graphene integrated with a network of metal nanowires; wherein
the optical device comprises a II-VI compound semiconductor, a III-V compound semiconductor, or InAsSb; and
said optically transparent and electrically conducting conductor forming electrical contacts and interconnects of an integrated circuit in said optical device; said electrical contacts and interconnects comprising at least a via hole interconnection; the via hole interconnection comprising a via hole coated with a passivation layer, said optically transparent and electrically conducting conductor being formed on the passivation layer on the sidewalls of the passivated via hole.

2. The optical device of claim 1 wherein the optical device further comprises an infrared optical device.

3. The optical device of claim 1 wherein the metal nanowires have an average diameter ranging from 10 nm to 150 nm.

4. The optical device of claim 1 wherein the conductor comprises:
metal nanowires with an average diameter of less than 150 nm, an average length of greater than 5 μm, a sheet resistance (Rs) of less than or equal to 100 Ω/sq., an optical transmittance (T λ ) greater than 85% in a visible to a short wavelength IR wavelength range and greater than or equal to 75% in a short wavelength IR to long wavelength IR wavelength range.

5. The optical device of claim 1 wherein the conductor comprises:
graphene with an optical transmittance (T λ ) of greater or equal to 85% from a visible to long wavelength infrared wavelength range.

6. A focal plane array comprising:
a detector array having a plurality of II-VI, III-V, or InAsSb detectors, each detector having an ohmic contact and a via hole having sidewalls passivated with a passivation layer;
a read out integrated circuit bonded to the detector array; and
a wideband transparent conductor coupled to the ohmic contact and through the via hole between each respective detector and a respective contact on the read out integrated circuit for conducting electrical signals between the detector and the read out integrated circuit; said wideband transparent conductor being formed on the passivation layer of said passivated sidewalls;
wherein the wideband transparent conductor comprises graphene, a network of metal nanowires, or graphene integrated with a network of metal nanowires.

7. The focal plane array of claim 6 wherein the wideband transparent conductor is transparent to infrared wavelengths.

8. The focal plane array of claim 6 wherein the via hole is in a semiconductor layer and the via hole further comprises a dielectric on the via hole to passivate the via hole.

9. The focal plane array of claim 6 wherein the metal nanowires have an average diameter ranging from 10 nm to 150 nm.

10. The focal plane array of claim 6 wherein:
the wideband transparent conductor comprises metal nanowires integrated with ultra thin metal film having a thickness less than 10 nm.

11. The focal plane array of claim 6 wherein:
each detector of the plurality of detectors is less than or equal to 10 μm×10 μm in area.

12. The focal plane array of claim 6 wherein the detectors operate in a wavelength range between visible wavelengths and long wavelength infrared wavelengths.

13. The focal plane array of claim 6 wherein the wideband transparent conductor comprises:
metal nanowires with an average diameter of less than 150 nm, an average length of greater than 5 μm, a sheet resistance (Rs) of less than or equal to 100 Ω/sq., an optical transmittance (T λ ) greater than 85% in a visible to a short wavelength IR wavelength range and greater than or equal to 75% in a short wavelength IR to long wavelength IR wavelength range.

14. The focal plane array of claim 6 wherein the wideband transparent conductor comprises:
graphene with an optical transmittance (T λ ) of greater than or equal to 85% from a visible to long wavelength infrared wavelength range.

15. A method of making a focal plane array comprising:
providing a detector array having a plurality of II-VI, III-V, or InAsSb detectors, each detector having an ohmic contact and a via hole having passivated sidewalls;
bonding a read out integrated circuit to the detector array; and
forming a wideband transparent conductor coupled to the ohmic contact and through the via hole having passivated sidewalls between each respective detector and a respective contact on the read out integrated circuit for conducting electrical signals between the detector and the read out integrated circuit;
wherein the wideband transparent conductor comprises graphene, a network of metal nanowires, or graphene integrated with a network of metal nanowires.

16. The method of claim 15 wherein the wideband transparent conductor is transparent to infrared wavelengths.

17. The method of claim 15 wherein the via hole is formed in a semiconductor layer and the via hole further comprises a dielectric on a sidewall of the via hole to passivate the via hole.

18. The method of claim 15 wherein the metal nanowires have an average diameter ranging from 10 nm to 150 nm.

19. The method of claim 15 wherein:
the ohmic contact of the wideband transparent conductor to the detector comprises metal nanowires having a diameter of less than or equal to 150 nm; and
a wideband transparent conductor on a sidewall of the via hole comprises metal nanowires having a diameter of less than or equal to 70 nm.

20. The method of claim 15 wherein:
the wideband transparent conductor comprises metal nanowires integrated with ultra thin metal film having a thickness less than 10 nm.

21. The method of claim 15 wherein:
each detector of the plurality of detectors is less than or equal to 10 μm×10 μm in area.

22. The method of claim 15 wherein the detectors operate in a wavelength range between visible wavelengths and long wavelength infrared wavelengths.

23. The method of claim 15 wherein the wideband transparent conductor comprises:
metal nanowires with an average diameter of less than 150 nm, an average length of greater than 5 μm, a sheet resistance (Rs) less than or equal to 100 Ω/sq., an optical transmittance (T λ ) greater than 85% in a visible to a short wavelength IR wavelength range and greater than or equal to 75% in the short wavelength IR to long wavelength IR wavelength range.

24. The method of claim 15 wherein the wideband transparent conductor comprises:
graphene with an optical transmittance (T λ ) of greater than or equal to 85% from a visible to long wavelength infrared wavelength range.

25. An optical device comprising:
an optically transparent and electrically conducting conductor comprising graphene, a network of metal nanowires, or graphene integrated with a network of metal nanowires; wherein the optical device comprises a II-VI compound semiconductor, a III-V compound semiconductor, or InAsSb; wherein:
the conductor comprises metal nanowires integrated with ultra thin metal film having a thickness less than 10 nm.

26. A focal plane array comprising:
a detector array having a plurality of II-VI, III-V, or lnAsSb detectors, each detector having an ohmic contact and a via hole;
a read out integrated circuit bonded to the detector array; and
a wideband transparent conductor coupled to the ohmic co

Assignees

• Hrl Lab Llc

Inventors

• Son Kyung-Ah
• Sharifi Hasan
• Moon Jeong-Sun
• Wong Wah S
• Seo Hwa Chang

Classifications

• H01L27/1469

  Electricity · mapped topic

• H01L27/14636

  Electricity · mapped topic

• H01L31/022466 Primary

  Electricity · mapped topic

• H01L31/022491

  Electricity · mapped topic

• H01L27/14634

  Electricity · mapped topic